Mumbai: More than 3,300 Mumbaikars tested positive for the mosquito-borne dengue infection during the June to Sept period, according to information shared by the BMC. However, concerns have been raised that the number of confirmatory tests conducted for monsoon diseases like dengue and leptospirosis is not adequate.While 12,444 rapid tests for dengue were done in 2024, 175 emerged positive. Of these, 15 were reconfirmed by ELISA tests and another 30 using the highly sensitive PCR method. Confirmatory tests are an important part of public health, as the union govt doesn’t accept rapid tests as a confirmation. “By not doing the second confirmatory test, the BMC has been reporting a lower incidence of dengue,” said a north Mumbai resident who sought data under the RTI Act from the BMC on the number of re-confirmatory tests done for monsoon diseases.In the case of leptospirosis, 11,161 cases were reported through rapid tests in 2024, but only 22 tests were reconfirmed by the PCR method. He said the BMC has barely reported 20-odd cases every year through reconfirmation. Globally, dengue is spreading rapidly, with the World Health Organisation estimating that 5 million cases occurred in 2023. India registered 290,000 cases in 2023 and 230,000 cases in 2024; Maharashtra registered around 19,000 in each of these years.Under the central health ministry’s directive, the number of surveillance and testing facilities was increased across the country, leading to a spurt in numbers in the past three years. However, the RTI information reveals that ELISA and PCR tests are not used in civic health centres and hospitals as often, despite being the more definitive tests.Dengue is a viral infection that is spread by the Aedes aegypti mosquitoes. There are four dengue viruses that can infect humans, with people likely to get long-term immunity against the type they are infected with. However, the first dengue infection is almost always mild, with subsequent infections becoming more serious. “The first infection is likely to be missed as it’s often considered to be flu,” said a doctor from a civic hospital. This could be one of the reasons for the tests not being used.However, a civic public health official said that reasons for using more rapid tests could range from a shortage of ELISA test kits. “Our PCR facility in Kasturba Hospital gets a good number of samples for dengue testing,” said the official. Moreover, the official added that confirmed cases are updated over a period of time due to reasons such as delayed data entry. “The state govt would have taken up such issues if testing was indeed low,” the official added.
